Low power electromagnetic pump
First Claim
1. An electromagnetic pump comprising:
- a) a housing having an interior fluid containing region including a fluid receiving chamber and a fluid output chamber in fluid communication therewith, an inlet in fluid communication with said receiving chamber and an outlet in fluid communication with said output chamber;
b) check valve means operatively associated with said fluid containing region for allowing fluid flow in a direction from said inlet through said outlet and blocking fluid flow in a direction from said outlet through said inlet;
c) electromagnet means carried by said housing and located external to said fluid containing region;
d) an armature positioned in said fluid containing region of said housing having a pole portion located for magnetic attraction by said electromagnet means and having a piston portion operatively associated with said fluid receiving and output chambers for forcing fluid from said receiving chamber through said outlet, said armature being movably supported in said housing for movement from a rest position through a forward pumping stroke when attracted by said electromagnet means to force fluid from said receiving chamber through said outlet and for movement in an opposite direction through a return stroke back to said rest position, said armature piston portion being located between a plunger portion and said pump inlet and movable within said housing, there being a relatively small clearance between said armature piston portion and said housing;
e) means defining a magnetic circuit including said electromagnet means and said armature and a gap between said pole portion of said armature and said electromagnet means for moving said armature toward said electromagnet means to close said gap in response to electrical energization of said electromagnet means;
f) controlled means for providing a bypass path for bubbles in the fluid around said armature piston portion between said fluid output chamber and said fluid receiving chamber only during said return stroke of said armature; and
g) means in said bypass path for providing an orifice for fluid flow in the bypass path so as to decelerate the flow of fluid through the pump and limit the inertial flow volume in the pump.
12 Assignments
0 Petitions
Accused Products
Abstract
An electromagnetic pump comprising a housing having fluid receiving and pumping chambers in communication with an inlet and outlet, respectively, an electromagnet carried by the housing external to the fluid chambers thereof, and an armature movable in the housing having a pole portion magnetically attracted by the electromagnet and a piston portion to force fluid out of the chambers and through the pump outlet. A path provides controlled bypass for bubbles in the fluid around the armature piston portion between the fluid pumping chamber and the fluid receiving chamber only during the return stroke of the armature.
Fluid inertia is reduced by an outlet orifice in the path of fluid flow from the pump outlet and by a bypass orifice for fluid flow in the bypass path, the orifices being provided either individually or in combination depending upon the fluid flow characteristics of the system including the pump. An accumulator in the fluid flow path between the pump outlet and a catheter leading away from the pump alleviates inertial and viscous effects arising from the catheter. The armature pole portion has a fluid-contacting section of material which is compatible with and corrosion resistant to the fluid, which can be a body of magnetic material within a titanium enclosure or a body of chrome-molybdenum-iron alloy. The check valve and inlet are so arranged that the pump displacement can be reduced without reducing the bubble pumping capability of the pump.
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Citations
22 Claims
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1. An electromagnetic pump comprising:
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a) a housing having an interior fluid containing region including a fluid receiving chamber and a fluid output chamber in fluid communication therewith, an inlet in fluid communication with said receiving chamber and an outlet in fluid communication with said output chamber; b) check valve means operatively associated with said fluid containing region for allowing fluid flow in a direction from said inlet through said outlet and blocking fluid flow in a direction from said outlet through said inlet; c) electromagnet means carried by said housing and located external to said fluid containing region; d) an armature positioned in said fluid containing region of said housing having a pole portion located for magnetic attraction by said electromagnet means and having a piston portion operatively associated with said fluid receiving and output chambers for forcing fluid from said receiving chamber through said outlet, said armature being movably supported in said housing for movement from a rest position through a forward pumping stroke when attracted by said electromagnet means to force fluid from said receiving chamber through said outlet and for movement in an opposite direction through a return stroke back to said rest position, said armature piston portion being located between a plunger portion and said pump inlet and movable within said housing, there being a relatively small clearance between said armature piston portion and said housing; e) means defining a magnetic circuit including said electromagnet means and said armature and a gap between said pole portion of said armature and said electromagnet means for moving said armature toward said electromagnet means to close said gap in response to electrical energization of said electromagnet means; f) controlled means for providing a bypass path for bubbles in the fluid around said armature piston portion between said fluid output chamber and said fluid receiving chamber only during said return stroke of said armature; and g) means in said bypass path for providing an orifice for fluid flow in the bypass path so as to decelerate the flow of fluid through the pump and limit the inertial flow volume in the pump. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An electromagnetic pump comprising:
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a) a housing having an interior fluid containing region including a fluid receiving chamber and a fluid output chamber in fluid communication therewith, an inlet in fluid communication with said receiving chamber and an outlet in fluid communication with said output chamber; b) check valve means operatively associated with said fluid containing region for allowing fluid flow in a direction from said inlet through said outlet and blocking fluid flow in a direction from said outlet through said inlet; c) electromagnet means carried by said housing and located external to said fluid containing region; d) barrier means of fluid-impervious material for isolating said electromagnet means from said fluid containing region of said housing; e) an armature positioned in said fluid containing region of said housing having a pole portion located for magnetic attraction by said electromagnet means and having a piston portion operatively associated with said fluid receiving and output chambers for forcing fluid from said receiving chamber through said outlet, said armature being movably supported in said housing for movement from a rest position through a forward pumping stroke when attracted by said electromagnet means to force fluid from said receiving chamber through said outlet and for movement in an opposite direction through a return stroke back to said rest position, said armature piston portion being located between a plunger portion and said pump inlet and movable within said housing, there being a relatively small clearance between said armature piston portion and said housing; f) said housing being elongated having a longitudinal axis, said armature being positioned for movement along said housing longitudinal axis, and said fluid containing region of said housing and said electromagnet means being in axially spaced relation along said housing longitudinal axis; g) said armature pole portion occupying a major portion of the fluid output chamber in which it is located and having a lateral dimension several times greater than the longitudinal dimension thereof; h) said armature pole portion having a fluid-contacting section of material which is compatible with and corrosion resistant to the fluid delivered by said system; and i) means defining a magnetic circuit including said electromagnet means and said armature and a gap between pole portion of said armature and said electromagnet means for moving said armature toward said electromagnet means to close said gap in response to electrical energization of said electromagnet means; j) so that during said forward pumping stroke of said armature there is a reduction in the internal volume of the pump downstream of said piston and there is a corresponding increase in the internal volume of the pump upstream of said piston and during said forward pumping stroke fluid flows in through said pump inlet to fill the increased internal volume upstream of said piston and fluid flows out through said pump outlet to accommodate the decreased internal volume downstream of said piston and so that during said return stroke of said armature the internal volume upstream of said piston decreases and fluid is removed therefrom and the internal volume downstream of said piston increases and fluid is supplied thereto. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. An electromagnetic pump comprising:
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a) a housing having an interior fluid containing region including a fluid receiving chamber and a fluid output chamber in fluid communication therewith, an inlet in fluid communication with said receiving chamber and an outlet in fluid communication with said output chamber; b) check valve means operatively associated with said fluid containing region for allowing fluid flow in a direction from said inlet through said outlet and blocking fluid flow in a direction from said outlet through said inlet; c) electromagnet means carried by said housing and located external to said fluid containing region; d) barrier means of fluid-impervious material for isolating said electromagnet means from said fluid containing region of said housing; e) an armature positioned in said fluid containing region of said housing having a pole portion located for magnetic attraction by said electromagnet means and having a piston portion operatively associated with said fluid receiving and output chambers for forcing fluid from said receiving chamber through said outlet, said armature being movably supported in said housing for movement from a rest position through a forward pumping stroke when attracted by said electromagnet means to force fluid from said receiving chamber through said outlet and for movement in an opposite direction through a return stroke back to said rest position, said armature piston portion being located between a plunger portion and said pump inlet and movable within said housing, there being a relatively small clearance between said armature piston portion and said housing; f) said armature pole portion comprising a solid body exclusively of magnetic material occupying a major portion of the fluid output chamber in which it is located and having a lateral dimension several times greater than the longitudinal dimension thereof, said magnetic material consisting essentially of a heat treated alloy of chrome, molybdenum and iron; and g) means defining a magnetic circuit including said electromagnet means and said armature and a gap between said pole portion of said armature and said electromagnet means for moving said armature toward said electromagnet means to close said gap in response to electrical energization of said electromagnet means; h) so that during said forward pumping stroke of said armature there is a reduction in the internal volume of the pump downstream of said piston and there is a corresponding increase in the internal volume of the pump upstream of said piston and during said forward pumping stroke fluid flows in through said pump inlet to fill the increased internal volume upstream of said piston and fluid flows out through said pump outlet to accommodate the decreased internal volume downstream of said piston and so that during said return stroke of said armature the internal volume upstream of said piston decreases and fluid is removed therefrom and the internal volume downstream of said piston increases and fluid is supplied thereto. - View Dependent Claims (20, 21, 22)
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Specification